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Stoneley Wave
A Stoneley wave is a boundary wave (or interface wave) that typically propagates along a solid-solid interface. When found at a liquid-solid interface, this wave is also referred to as a Scholte wave. The wave is of maximum intensity at the interface and decreases exponentially away from it. It is named after the British seismologist Dr. Robert Stoneley (1894–1976), a lecturer in the University of Leeds, who discovered it on October 1, 1924. Occurrence and use Stoneley waves are most commonly generated during borehole sonic logging and vertical seismic profiling. They propagate along the walls of a fluid-filled borehole. They make up a large part of the low-frequency component of the signal from the seismic source and their attenuation is sensitive to fractures and formation permeability. Recent studies have found that Stoneley wave processing in borehole help to distinguish between fractured versus non-fractured coal seam. Therefore, analysis of Stoneley waves can make it ...
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Stoneley Wave
A Stoneley wave is a boundary wave (or interface wave) that typically propagates along a solid-solid interface. When found at a liquid-solid interface, this wave is also referred to as a Scholte wave. The wave is of maximum intensity at the interface and decreases exponentially away from it. It is named after the British seismologist Dr. Robert Stoneley (1894–1976), a lecturer in the University of Leeds, who discovered it on October 1, 1924. Occurrence and use Stoneley waves are most commonly generated during borehole sonic logging and vertical seismic profiling. They propagate along the walls of a fluid-filled borehole. They make up a large part of the low-frequency component of the signal from the seismic source and their attenuation is sensitive to fractures and formation permeability. Recent studies have found that Stoneley wave processing in borehole help to distinguish between fractured versus non-fractured coal seam. Therefore, analysis of Stoneley waves can make it ...
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Scholte Wave
A Scholte wave is a surface wave (interface wave) propagating at an interface between a fluid and an elastic solid medium (such as an interface between water and sand). The wave is of maximum intensity at the interface and decreases exponentially away from the interface into both the fluid and the solid medium. It is named after J. G. Scholte, who discovered it in 1947. This wave is similar to a Stoneley wave, which propagates at a solid-solid interface, and a Rayleigh wave Rayleigh waves are a type of surface acoustic wave that travel along the surface of solids. They can be produced in materials in many ways, such as by a localized impact or by piezo-electric transduction, and are frequently used in non-destructi ..., which propagates at a vacuum-solid interface. References {{Reflist Surface waves ...
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University Of Leeds
, mottoeng = And knowledge will be increased , established = 1831 – Leeds School of Medicine1874 – Yorkshire College of Science1884 - Yorkshire College1887 – affiliated to the federal Victoria University1904 – University of Leeds , type = Public , endowment = £90.5 million , budget = £751.7 million , chancellor = Jane Francis , vice_chancellor = Simone Buitendijk , students = () , undergrad = () , postgrad = () , city = Leeds , province = West Yorkshire , country = England , campus = Urban, suburban , free_label = Newspaper , free = The Gryphon , colours = , website www.leeds.ac.uk, logo = Leeds University logo.svg , logo_size = 250 , administrative_staff = 9,200 , coor = , affiliations = The University of Leeds is a public research university in Leeds, West Yorkshire, England. It was established in 1874 as the Yorkshire College of Science. In 1884 it merged with the Leeds School of Medicine (established 1831) and was renam ...
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Sonic Logging
Sonic logging is a well logging tool that provides a formation’s interval transit time, designated as t, which is a measure of a how fast elastic seismic compressional and shear waves travel through the formations. Geologically, this capacity varies with many things including lithology and rock textures, most notably decreasing with an increasing effective porosity and increasing with an increasing effective confining stress. This means that a sonic log can be used to calculate the porosity, confining stress, or pore pressure of a formation if the seismic velocity of the rock matrix, V_, and pore fluid, V_l, are known, which is very useful for hydrocarbon exploration. Process of sonic logging The velocity is calculated by measuring the travel time from the piezoelectric transmitter to the receiver, normally with the units microsecond per foot (a measure of slowness). To compensate for the variations in the drilling mud thickness, there are actually two receivers, one near ...
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Vertical Seismic Profile
In geophysics, vertical seismic profile (VSP) is a technique of seismic measurements used for correlation with surface seismic data. The defining characteristic of a VSP (of which there are many types) is that either the energy source, or the detectors (or sometimes both) are in a borehole. In the most common type of VSP, hydrophones, or more often geophones or accelerometers, in the borehole record reflected seismic energy originating from a seismic source at the surface. There are numerous methods for acquiring a vertical seismic profile (VSP). Zero-offset VSPs (A) have sources close to the wellbore directly above receivers. Offset VSPs (B) have sources some distance from the receivers in the wellbore. Walkaway VSPs (C) feature a source that is moved to progressively farther offset and receivers held in a fixed location. Walk-above VSPs (D) accommodate the recording geometry of a deviated well, having each receiver in a different lateral position and the source directly above the ...
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Borehole
A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petroleum), or gases (such as natural gas). It may also be part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage. Importance Engineers and environmental consultants use the term ''borehole'' to collectively describe all of the various types of holes drilled as part of a geotechnical investigation or environmental site assessment (a so-called Phase II ESA). This includes holes advanced to collect soil samples, water samples or rock cores, to advance ''in situ'' sampling equipment, or to install monitoring ...
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Energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light. Energy is a conserved quantity—the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J). Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object (for instance due to its position in a field), the elastic energy stored in a solid object, chemical energy associated with chemical reactions, the radiant energy carried by electromagnetic radiation, and the internal energy contained within a thermodynamic system. All living organisms constantly take in and release energy. Due to mass–energy equivalence, any object th ...
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Katsutada Sezawa
Katsutada Sezawa (, 21 August 1895 – 23 April 1944) was a Japanese geophysicist ( Seismologist). Sezawa's key work was on the mathematical aspects of wave transmission in media of different viscosities and the Sezawa wave mode of surface waves is named after him. Sezawa was born in Ishikawa Prefecture where his father was a judge. He graduated in 1921 from the Imperial University of Tokyo in shipbuilding and became a professor at the university in 1928. Sezawa became the director of the Earthquake Research Institute, University of Tokyo. His key work was on theoretical aspects of seismic wave transmission in different media. He was able to calculate differences in the structure of the earth based on seismic observations. He also predicted the existence of surface waves which are now termed as Sezawa waves. He was awarded the Imperial Prize of the Japan Academy The is a prestigious honor conferred to two of the recipients of the Japan Academy Prize. Overviews It is a ...
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Velocity
Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies. Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called , being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s or m⋅s−1). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the object is said to be undergoing an ''acceleration''. Constant velocity vs acceleration To have a ''constant velocity'', an object must have a constant speed in a constant direction. Constant directi ...
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